Dr. Hans Plen. "World Politics. An Essay on the Most Recent World History Following the Conclusion of the Anglo-Japanese Alliance." Berlin, 1907 (pp. 214), 3rd edition. A fairly decent essay, devoted for the most part to England and Japan (in connection with them, also to America and Russia. England - Japan - United States - Russia).

In the second part (pp. 91-167) on the organization of foreign policy in England (not the state, but "society").